Problem: Ashley ate 4 slices of cake. William ate 3 slices. If Ashley ate $\dfrac{4}{9}$ of the cake, what fraction of the cake was eaten?
Answer: If 4 slices represent $\dfrac{4}{9}$ of the cake, there must have been a total of 9 slices. $\text{fraction of cake eaten} = \dfrac{\text{number of slices eaten}}{\text{number of slices total}}$ They ate ${7}$ out of $9$ slices. They ate $\dfrac{7}{9}$ of the cake.